Track gauge adjusting system of crawler-type transplanter

Abstract

The track gauge adjusting system comprises a transplanter chassis support, two track wheel modules are detachably installed on the two sides of the lower portion of the transplanter chassis support in a modularized mode, and a track frame of each track wheel module is connected with the transplanter chassis support through a track gauge adjusting unit. The track gauge between the two crawler wheel modules can be adjusted through the track gauge adjusting unit; the mechanism capable of dynamically adjusting the track gauge is designed and can adapt to various ridge surfaces and operation scenes, and the universality of equipment is improved.

Description

Technical Field

[0001] The present invention belongs to the field of track gauge adjustment of transplanting machines. Background Art

[0002] Traditional strawberry transplanting machines mostly adopt a fixed track gauge design, which cannot be flexibly adjusted according to the row spacing of different crops or terrain conditions, and thus cannot meet the requirements of different crop ridges and terrain. Traditional machinery needs to frequently replace components or adjust the structure, resulting in low efficiency. The fixed structure is difficult to cope with complex working environments or diverse workpieces, leading to low transplanting accuracy and high seedling damage rate. Summary of the Invention

[0003] Object of the Invention: In order to overcome the deficiencies in the prior art, the present invention provides a track gauge adjustment system for a crawler-type transplanting machine, which realizes the track gauge adjustment between two crawler wheel modules through modular design.

[0004] Technical Solution: To achieve the above object, a track gauge adjustment system for a crawler-type transplanting machine of the present invention includes a chassis bracket of the transplanting machine. Two crawler wheel modules are modularly and detachably installed on both sides of the lower part of the chassis bracket of the transplanting machine. The crawler frames of each crawler wheel module are connected to the chassis bracket of the transplanting machine through a track gauge adjustment unit, and the track gauge between the two crawler wheel modules can be adjusted through the track gauge adjustment unit.

[0005] Furthermore, the adjustment of each track gauge adjustment unit includes two track gauge adjustment platforms distributed front and back above the crawler wheel module. The track gauge adjustment platforms are fixedly connected to the crawler frame through vertical structural arms;

[0006] Each installation platform corresponding to each track gauge adjustment platform is fixedly arranged on the chassis bracket of the transplanting machine;

[0007] In the working state, the track gauge adjustment platform is horizontally attached to the lower surface of the corresponding installation platform, and is positioned and locked through a positioning structure and a locking structure.

[0008] Furthermore, an a positioning hole is provided on the track gauge adjustment platform, and a plurality of b positioning holes are equidistantly arrayed in the vertical direction perpendicular to the traveling direction of the transplanting machine on the installation platform; It also includes a positioning pin that can align the a positioning hole with any b positioning hole for positioning.

[0009] Furthermore, a locking holes are provided on both sides of the a positioning hole of the track gauge adjustment platform; a plurality of b locking holes are equidistantly arrayed in the vertical direction perpendicular to the traveling direction of the transplanting machine on both sides of the plurality of b positioning holes on the installation platform; When the a positioning hole is aligned with any b positioning hole, each a locking hole must be aligned with a b locking hole;

[0010] The a locking hole and the aligned b locking hole are locked to each other through a detachable bolt locking member.

[0011] The positioning pin includes an upper pin section and a lower pin section, and a chamfer is provided at the upper end of the upper pin section; in the assembled state, the upper pin section and the lower pin section are respectively in the b positioning hole and the a positioning hole.

[0012] Further, the a positioning hole is a non-through counterbore with a smooth inner wall surface; the b positioning hole is a through hole with a smooth inner wall; the outer diameters of the upper pin section and the lower pin section are respectively consistent with the inner diameters of the b positioning hole and the a positioning hole.

[0013] Further, the a positioning hole is a non-through internal thread counterbore with a threaded inner wall surface; the b positioning hole is a through hole with a smooth inner wall; the outer diameter of the upper pin section is smaller than the inner diameter of the b positioning hole; the outer wall of the lower pin section is an external thread that mates with the internal thread of the a positioning hole;

[0014] A central hydraulic piston channel with a closed upper end is coaxially arranged inside the positioning pin, a central hydraulic piston is arranged in the central hydraulic piston channel, and a return spring is arranged in the central hydraulic piston channel;

[0015] A central universal ball rod extending downward is fixedly connected to the lower end of the central hydraulic piston, and a central universal ball is rotatably arranged at the lower end of the central universal ball rod;

[0016] A number of circumferential hydraulic piston channels extending in the radial direction are arranged in a circumferential array on the upper pin section. One end of each circumferential hydraulic piston channel close to each other communicates with the central hydraulic piston channel, and a piston limiting inner edge is provided on the inner wall of the end of each circumferential hydraulic piston channel away from each other;

[0017] A radial propulsion hydraulic piston is arranged in each circumferential hydraulic piston channel. A columnar universal ball seat is coaxially fixedly connected to the end of the radial propulsion hydraulic piston away from the central hydraulic piston channel, and a radial propulsion universal ball is rotatably arranged in the universal ball seat; the inner diameter of the piston limiting inner edge is not less than the outer diameter of the universal ball seat.

[0018] Further, in the initial state: the lower end of the central universal ball rod protrudes a certain distance from the lower end of the lower pin section; the external thread of the lower pin section is threadedly engaged with the internal thread of the a positioning hole, there is a certain distance between the lower end of the lower pin section and the bottom surface of the a positioning hole, and the lower end of the central universal ball is in rolling fit with the bottom surface of the a positioning hole; the universal ball seat and the radial propulsion universal ball are both in the circumferential hydraulic piston channel;

[0019] When the central hydraulic piston moves upward, a number of radial propulsion hydraulic pistons move away from each other along the radial direction of the upper pin section under the propulsion of the hydraulic pressure, so that each radial propulsion universal ball gradually protrudes from the outer peripheral surface of the upper pin section;

[0020] When the lowermost end of the central universal ball is level with the lower end of the lower section of the pin, each radial propulsion hydraulic piston just pushes outwards to the inner edge of the limit of the limit-fitting piston. At this time, if the upper section of the pin is in the b positioning hole, then at this time, each radial propulsion universal ball around the upper section of the pin just tangentially contacts the inner wall of the b positioning hole where it is located.

[0021] Furthermore, after the upper sections of the positioning pins are all inserted upwards into the new b positioning holes, almost simultaneously, slowly rotate each positioning pin in the positive direction synchronously, so that the lower sections of the positioning pins gradually sink further into the a positioning hole under the drive of the thread. When the lower sections of the pins are completely sunk into the a positioning hole under the drive of the thread, positioning is achieved.

[0022] Beneficial effects: The mechanism for dynamically adjusting the gauge designed in the present invention can adapt to a variety of ridge surfaces and working scenarios, improving the versatility of the equipment; the crawler and the chassis frame adopt a split design, and the connection method is pin connection. Five different gauges are preset. When changing the gauge, the frame can be lifted to pull out the pins and inserted into different preset hole positions to achieve gauge switching; the gauge adjustment range is extended to 0.8 m to 1.2 m, covering the requirements of different crop ridge surfaces, and the frequency of manual intervention is reduced by 80%. Description of the Drawings

[0023] Figure 1 is the overall schematic diagram of this solution;

[0024] Figure 2 is Figure 1 a partial schematic diagram of

[0025] Figure 3 is the schematic diagram of a single set of crawler wheel modules;

[0026] Figure 4 is the schematic diagram of the positioning pin of the first embodiment;

[0027] Figure 5 is the schematic diagram of the positioning pin of the second embodiment. Detailed Embodiment

[0028] The present invention will be further described below with reference to the drawings.

[0029] As shown in the attached Figures 1 to 5 A gauge adjustment system for a crawler-type transplanter includes a transplanter chassis bracket 3. Two crawler wheel modules 1 are modularly and detachably installed on both sides of the lower part of the transplanter chassis bracket 3. The crawler frames 2 of each crawler wheel module 1 are all connected to the transplanter chassis bracket 3 through a gauge adjustment unit. The core feature of this case is that the gauge between the two crawler wheel modules 1 can be adjusted through the gauge adjustment unit; the mechanism for dynamically adjusting the gauge designed in the present invention can adapt to a variety of ridge surfaces and working scenarios, improving the versatility of the equipment.

[0030] The adjustment of each gauge adjustment unit includes two gauge adjustment platforms 8 distributed front and back above the crawler wheel module 1. The gauge adjustment platform 8 is fixedly connected to the crawler frame 2 through a vertical structural arm 11. Each installation platform 9 corresponding to each gauge adjustment platform 8 is fixedly arranged on the transplanting machine chassis bracket 3.

[0031] In the working state, the gauge adjustment platform 8 is horizontally attached to the lower surface of the corresponding installation platform 9 and is positioned and locked by a positioning structure and a locking structure.

[0032] An a-positioning hole 6 is arranged on the gauge adjustment platform 8, and a plurality of b-positioning holes 4 are equidistantly arrayed along the vertical direction perpendicular to the driving direction of the transplanting machine on the installation platform 9. It also includes a positioning pin 10 that can align the a-positioning hole 6 with any b-positioning hole 4 for positioning.

[0033] On both sides of the a-positioning hole 4 of the gauge adjustment platform 8, a-locking holes 7 are arranged. On both sides of the plurality of b-positioning holes 4 on the installation platform 9, a plurality of b-locking holes 4 are equidistantly arrayed along the vertical direction perpendicular to the driving direction of the transplanting machine. When the a-positioning hole 6 is aligned with any b-positioning hole 4, each a-locking hole 7 must be aligned with a b-locking hole 4. The a-locking hole 7 and the aligned b-locking hole 4 are locked to each other by a detachable bolt locking member.

[0034] The positioning pin 10 includes an upper pin section 13 and a lower pin section 14. A chamfer is arranged at the upper end of the upper pin section 13. In the assembled state, the upper pin section 13 and the lower pin section 14 are respectively in the b-positioning hole 4 and the a-positioning hole 6, so as to achieve the positioning function. In this solution, when the a-positioning hole 6 is aligned with different b-positioning holes 4, the distance between the two crawler wheel modules 1 will change accordingly, thus realizing the adjustability of the gauge between the two crawler wheel modules 1.

[0035] Based on the above basic structure, the positioning structure of this solution provides the following two embodiments:

[0036] The first embodiment:

[0037] Such as Figure 3 and 4 , the a-positioning hole 6 is a non-through counterbore with a smooth inner wall surface; the b-positioning hole 4 is a through hole with a smooth inner wall; the outer diameters of the upper pin section 13 and the lower pin section 14 are respectively the same as the inner diameters of the b-positioning hole 4 and the a-positioning hole 6.

[0038] The working principle of the first embodiment:

[0039] Since the two crawler wheel modules 1 are symmetric left and right, one of them is taken as an example for description; the gauge adjustment process of the first embodiment:

[0040] Step 1: First, remove the bolt locking parts connecting the a locking holes 7 and the aligned b locking holes 4. Then, manually or using tools, lift the transplanting machine chassis bracket 3 in a horizontal posture upward. The crawler wheel module 1 remains in its original position under the action of gravity, thus realizing the separation of the crawler wheel module 1 from the transplanting machine chassis bracket 3. At the same time, the lower section 14 of the pin of each positioning pin 10 still remains in the a positioning hole 6, and the upper section 13 of the pin of the positioning pin 10 is separated from the originally inserted b positioning hole 4;

[0041] Step 2: Then, use tools or manually translate the crawler wheel module 1 in the vertical direction perpendicular to the driving direction, so that the upper sections 13 of the pins of the positioning pins 10 are gradually translated to align with another b positioning hole 4, thereby realizing the adjustment of the track gauge;

[0042] Step 3: Slowly lower the transplanting machine chassis bracket 3 lifted in "Step 1", so that the upper sections 13 of the pins of the positioning pins 10 are all inserted upward into the new b positioning holes 4, so that each a positioning hole 6 is aligned with a new b positioning hole 4; Since when any a positioning hole 6 is aligned with a b positioning hole 4, each a locking hole 7 is necessarily aligned with a b locking hole 4, thus realizing the function of precise positioning. Therefore, finally, the a locking holes 7 and the aligned b locking holes 4 are locked to each other through detachable bolt locking parts, thus realizing the complete assembly process after changing the track gauge.

[0043] In practice, even though there is a chamfer guide on the upper section 13 of the pin, due to the requirement of precise positioning, the outer diameter of the upper section 13 of the positioning pin 10 is the same as the inner diameter of the b positioning hole 4, and still requires final precise alignment to be smoothly inserted. Otherwise, it is easy to cause problems such as scratching or misalignment. Moreover, during the process of the upper section 13 of the positioning pin 10 in "Step 3" being gradually translated to align with another b positioning hole 4, if the lifted transplanting machine chassis bracket 3 has slight attitude problems such as slight front-back height inclination or horizontal deviation, it will cause the upper sections 13 of the positioning pins 10 to be difficult to simultaneously align with their corresponding b positioning holes 4, and thus there is a problem of difficult alignment at the operation level. For this reason, the following second embodiment is designed:

[0044] Second embodiment:

[0045] As Figure 5 shown, the a positioning hole 6 is a non-through internal thread counterbore with a threaded inner wall surface; the b positioning hole 4 is a smooth inner wall through hole; the outer diameter of the upper section 13 of the pin is smaller than the inner diameter of the b positioning hole 4; the outer wall of the lower section 14 of the pin is an external thread that mates with the internal thread of the a positioning hole 6; a hexagonal counterbore 15 is provided at the upper end of the upper section 13 of the pin.

[0046] A central hydraulic plunger passage 24 with a closed upper end is coaxially arranged inside the positioning pin 10. A central hydraulic piston 23 is arranged in the central hydraulic plunger passage 24. The central hydraulic plunger passage 24 above the central hydraulic piston 23 is filled with hydraulic oil. A return spring 25 is arranged in the central hydraulic piston 23 and the central hydraulic plunger passage 24. The lower end of the return spring 25 forms a downward elastic thrust on the central hydraulic piston 23, so that the lower end of the central hydraulic piston 23 is in limiting fit with the limiting step 30 on the inner wall of the central hydraulic plunger passage 24.

[0047] A central universal ball rod 22 extending downward is fixedly connected to the lower end of the central hydraulic piston 23. A central universal ball 21 is rotatably arranged at the lower end of the central universal ball rod 22. In the initial state, the lower end of the central universal ball rod 22 protrudes a certain distance below the lower end of the lower pin segment 14.

[0048] In the initial state, the external thread of the lower pin segment 14 is in threaded fit with the internal thread of the a-positioning hole 6. There is a certain distance between the lower end of the lower pin segment 14 and the bottom surface of the a-positioning hole 6, and the lower end of the central universal ball 21 is in rolling fit with the bottom surface of the a-positioning hole 6;

[0049] A number of circumferential hydraulic piston passages 19 extending in the radial direction are arranged in a circumferential array on the upper pin segment 13. One end of each circumferential hydraulic piston passage 19 close to each other communicates with the central hydraulic plunger passage 24. The inner wall of one end of each circumferential hydraulic piston passage 19 away from each other is provided with a piston limiting inner edge 18.

[0050] A radial propulsion hydraulic piston 20 is arranged in each circumferential hydraulic piston passage 19. A columnar universal ball seat 16 is fixedly connected to the end of the radial propulsion hydraulic piston 20 away from the central hydraulic plunger passage 24. A radial propulsion universal ball 17 is rotatably arranged in the universal ball seat 16; the inner diameter of the piston limiting inner edge 18 is not less than the outer diameter of the universal ball seat 16.

[0051] In the initial state, both the universal ball seat 16 and the radial propulsion universal ball 17 are in the circumferential hydraulic piston passage 19. When the central hydraulic piston 23 moves upward, a number of radial propulsion hydraulic pistons 20 move away from each other in the radial direction of the upper pin segment 13 under the propulsion of hydraulic pressure, so that each radial propulsion universal ball 17 gradually protrudes from the outer peripheral surface of the upper pin segment 13; when the lowermost end of the central universal ball 21 is flush with the lower end of the lower pin segment 14, each radial propulsion hydraulic piston 20 just moves outward to be in limiting fit with the piston limiting inner edge 18. At this time, if the upper pin segment 13 is in the b-positioning hole 4, then each radial propulsion universal ball 17 around the upper pin segment 13 is just tangent to the inner wall of the b-positioning hole 4 where it is located.

[0052] The gauge adjustment process of the second embodiment:

[0053] Step 1: First, remove all the bolt locking parts connecting the a locking holes 7 and the aligned b locking holes 4. Then, manually or using tools, lift the transplanting machine chassis bracket 3 in a horizontal position upward. The crawler wheel module 1 remains in its original position under the action of gravity, thus realizing the separation of the crawler wheel module 1 from the transplanting machine chassis bracket 3. At this time, the upper section 13 of the positioning pin 10 is separated from the originally inserted b positioning hole 4. At this time, use a hex wrench to rotate each positioning pin 10 in the reverse direction, so that the lower end of the lower section 14 of the pin forms a certain distance from the bottom surface of the a positioning hole 6. The lower end of the central universal ball 21 rolls and fits with the bottom surface of the a positioning hole 6. Each universal ball seat 16 and the radial propulsion universal ball 17 in the positioning pin 10 are both in the circumferential hydraulic piston channel 19. At this time, it is the initial state of the positioning pin 10.

[0054] Step 2: Then, use tools or manually translate the crawler wheel module 1 in the vertical direction perpendicular to the driving direction, so that the upper section 13 of each positioning pin 10 is gradually translated until it is visually aligned with another b positioning hole 4, thereby realizing the adjustment of the track gauge. In this step, since the outer diameter of the upper section 13 of the pin is significantly smaller than the inner diameter of the b positioning hole 4, the alignment of the upper section 13 of the positioning pin 10 with the b positioning hole 4 does not need to be very precise to complete, thus avoiding the problem of difficult alignment in "Step 3" of the "First Embodiment".

[0055] Step 3: Slowly lower the transplanting machine chassis bracket 3 lifted in "Step 1", so that the upper section 13 of each positioning pin 10 is inserted upward into the new b positioning hole 4. By the same principle, since the outer diameter of the upper section 13 of the pin is significantly smaller than the inner diameter of the b positioning hole 4, the upper section 13 of each positioning pin 10 can be smoothly and imprecisely inserted upward into the new b positioning hole 4, so that each a positioning hole 6 is imprecisely aligned with a new b positioning hole 4. At this time, each track gauge adjustment platform 8 is horizontally attached to and horizontally supports the corresponding installation platform 9 upward. At this time, it is equivalent to the transplanting machine chassis bracket 3 being horizontally placed and supported on the upper side of the two crawler wheel modules 1, but not completely locked yet. At the same time, at this time, each a positioning hole 6 and the corresponding b positioning hole 4 are not precisely aligned.

[0056] Step Four: Use an internal hexagon wrench to slowly and simultaneously rotate each positioning pin 10 in the positive direction almost at the same time, so that the lower pin section 14 of each positioning pin 10 gradually further sinks into the a-positioning hole 6 under the drive of the thread, thereby pushing the bottom of the a-positioning hole 6 upward relative to the central universal ball 21, causing the central hydraulic piston 23 to displace upward relative to the positioning pin 10, and further causing several radial propulsion hydraulic pistons 20 to move away from each other along the radial direction of the upper pin section 13 under the propulsion of hydraulic pressure, so that each radial propulsion universal ball 17 gradually protrudes from the outer peripheral surface of the upper pin section 13; when the lower pin section 14 completely sinks into the a-positioning hole 6 under the drive of the thread, the lower end of the lower pin section 14 just touches the bottom of the a-positioning hole 6, so that the lowermost end of the central universal ball 21 is flush with the lower end of the lower pin section 14. At this time, each radial propulsion hydraulic piston 20 just pushes outward to the inner edge 18 of the limit mating piston. Each radial propulsion universal ball 17 around the upper pin section 13 just tangentially contacts the inner wall of the corresponding b-positioning hole 4, so that the upper pin section 13 and the b-positioning hole 4 are precisely coaxial, so that the a-positioning hole 6 and the corresponding b-positioning hole 4 are precisely aligned. During the above process, the transplanting machine chassis bracket 3 adaptively offsets horizontally; at this time, since each a-locking hole 7 must be aligned with a b-locking hole 4 when the a-positioning hole 6 and the b-positioning hole 4 are aligned, finally, each a-locking hole 7 and the aligned b-locking hole 4 are locked to each other by a detachable bolt locking member, thus realizing the complete assembly process after changing the gauge; finally, each positioning pin 10 can be appropriately loosened.

[0057] In the "Step Two" and "Step Three" of this embodiment, a non-precise alignment method is adopted during the alignment stage. Therefore, the alignment of the upper pin section 13 of the positioning pin 10 and the b-positioning hole 4 does not need to be very precise to complete, thus avoiding the problem of difficult alignment that occurred in the "Step Three" of the "First Embodiment".

[0058] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A gauge adjustment system for a crawler transplanter, characterized in that: It includes a transplanting machine chassis bracket (3). On both sides of the lower part of the transplanting machine chassis bracket (3), two crawler wheel modules (1) are modularly and detachably installed. The crawler frames (2) of each crawler wheel module (1) are connected to the transplanting machine chassis bracket (3) through a gauge adjustment unit, and the gauge between the two crawler wheel modules (1) can be adjusted through the gauge adjustment unit.

2. The track gauge adjustment system of a crawler transplanter according to claim 1, characterized in that: The adjustment of each gauge adjustment unit includes two gauge adjustment platforms (8) distributed front and back above the crawler wheel module (1). The gauge adjustment platform (8) is fixedly connected to the crawler frame (2) through a vertical structural arm (11); On the transplanting machine chassis bracket (3), there are fixedly arranged installation platforms (9) corresponding to each gauge adjustment platform (8) one by one; In the working state, the gauge adjustment platform (8) is horizontally attached to the lower surface of the corresponding installation platform (9), and is positioned and locked through a positioning structure and a locking structure.

3. The track gauge adjustment system of a crawler transplanter according to claim 2, characterized in that: The gauge adjustment platform (8) is provided with an a positioning hole (6). On the installation platform (9), a number of b positioning holes (4) are equidistantly arrayed along the vertical direction perpendicular to the traveling direction of the transplanting machine; It also includes a positioning pin (10) that can align the a positioning hole (6) with any b positioning hole (4) for positioning.

4. The track gauge adjustment system of a crawler transplanter according to claim 3, characterized in that: On both sides of the a positioning hole (4) of the gauge adjustment platform (8), there are a locking holes (7); on both sides of the number of b positioning holes (4) on the installation platform (9), a number of b locking holes (4) are equidistantly arrayed along the vertical direction perpendicular to the traveling direction of the transplanting machine; when the a positioning hole (6) is aligned with any b positioning hole (4), each a locking hole (7) must be aligned with a b locking hole (4); the a locking hole (7) and the aligned b locking hole (4) are locked to each other through a detachable bolt locking member.

5. The track gauge adjustment system of a crawler transplanter according to claim 4, characterized in that: The positioning pin (10) includes an upper pin section (13) and a lower pin section (14); in the assembled state, the upper pin section (13) and the lower pin section (14) are respectively in the b positioning hole (4) and the a positioning hole (6).

6. The track gauge adjustment system of a crawler transplanter according to claim 5, characterized in that: The a positioning hole (6) is a non-through counterbore with a smooth inner wall surface; the b positioning hole (4) is a through hole with a smooth inner wall; the outer diameters of the upper pin section (13) and the lower pin section (14) are respectively the same as the inner diameters of the b positioning hole (4) and the a positioning hole (6).

7. The track gauge adjustment system of a crawler transplanter according to claim 5, characterized in that: The a positioning hole (6) is a non-through internal thread counterbore with a threaded inner wall surface; the b positioning hole (4) is a through hole with a smooth inner wall; the outer diameter of the upper pin section (13) is smaller than the inner diameter of the b positioning hole (4); the outer wall of the lower pin section (14) is an external thread that mates with the internal thread of the a positioning hole (6); Inside the positioning pin (10), a central hydraulic piston channel (24) with a closed upper end is coaxially arranged. A central hydraulic piston (23) is arranged in the central hydraulic piston channel (24), and a return spring (25) is arranged in the central hydraulic piston channel (24) of the central hydraulic piston (23); The lower end of the central hydraulic piston (23) is fixedly connected to a central universal ball rod (22) extending downward. The lower end of the central universal ball rod (22) is rotatably provided with a central universal ball (21); A number of circumferential hydraulic piston channels (19) extending in the radial direction are arranged in a circumferential and integral manner on the upper section (13) of the pin. One end of each circumferential hydraulic piston channel (19) close to each other communicates with the central hydraulic plunger channel (24). The inner wall of the end of each circumferential hydraulic piston channel (19) away from each other is provided with a piston limiting inner edge (18). A radial propulsion hydraulic piston (20) is arranged in each circumferential hydraulic piston channel (19). One end of the radial propulsion hydraulic piston (20) away from the central hydraulic plunger channel (24) is coaxially and fixedly connected with a columnar universal ball seat (16). A radial propulsion universal ball (17) is rotatably arranged in the universal ball seat (16). The inner diameter of the piston limiting inner edge (18) is not less than the outer diameter of the universal ball seat (16).

8. The track gauge adjustment system of a crawler transplanter according to claim 7, characterized in that: In the initial state: The lower end of the central universal ball rod (22) protrudes a certain distance below the lower end of the lower section (14) of the pin. The external thread of the lower section (14) of the pin is in threaded cooperation with the internal thread in the a positioning hole (6). There is a certain distance between the lower end of the lower section (14) of the pin and the bottom surface of the a positioning hole (6), and the lower end of the central universal ball (21) is in rolling cooperation with the bottom surface of the a positioning hole (6). The universal ball seat (16) and the radial propulsion universal ball (17) are both in the circumferential hydraulic piston channel (19). When the central hydraulic piston (23) moves upward, a number of radial propulsion hydraulic pistons (20) move away from each other along the radial direction of the upper section (13) of the pin under the propulsion of hydraulic pressure, so that each radial propulsion universal ball (17) gradually protrudes from the outer peripheral surface of the upper section (13) of the pin. When the lowermost end of the central universal ball (21) is flush with the lower end of the lower section (14) of the pin, each radial propulsion hydraulic piston (20) just advances outward to be in limiting cooperation with the piston limiting inner edge (18). At this time, if the upper section (13) of the pin is in the b positioning hole (4), then each radial propulsion universal ball (17) around the upper section (13) of the pin is just tangent to the inner wall of the corresponding b positioning hole (4).

9. The working method of the track gauge adjustment system of a crawler transplanter according to claim 8, characterized in that: After the upper sections (13) of each positioning pin (10) are inserted upward into the new b positioning holes (4), each positioning pin (10) is slowly and positively rotated synchronously almost at the same time, so that the lower sections (14) of each positioning pin (10) are gradually further inserted into the a positioning holes (6) under the drive of the thread. When the lower sections (14) of the pins are completely inserted into the a positioning holes (6) under the drive of the thread, positioning is achieved.

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